the diagram is being used to illustrate the second law of thermodynamics, where qh  represents a hot object and qcrepresents a cold object. which will  best  complete the diagram to illustrate the law? adding in the boxes an arrow that points from qh  to qcadding in the boxes an arrow that points from  qc  to  qhadding in the boxes an arrow that points in both directions between  qh  and  qcadding in each box an arrow that points upward fromqh  and from  qc

True will be your answer dude

An em wave does not require a medium, while a mechanical wave does. 

The answer is "iron"

Jenny and fred both play a long note on their trombones. a stationary observer hears the sound increasing and decreasing repeatedly in loudness. which of these must be true? the sound waves from the two trombones have slightly different frequencies.the sound waves from the two trombones have the same frequency.the sound waves from the two trombones have slightly different amplitudes.the sound waves from the two trombones have the same wavelength.the sound waves from the two trombones have slightly different velocities.  lolthe answer is          the sound waves from the two trombones have slightly different frequencies.